SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c3e7415deb6426d056025b97f91c003473ddf2a3d2268dd12ec199956fc28e4' 
  AND token = 'v5VF7JfmyxUm6jJ1gACVUMYydZCanAvWk1Hw26JQQXc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}